1810.8 Allowable stresses.
BC § 1810.8
Allowable stresses for deep foundations shall be as listed in Table 1810.8. Exception: Allowable stresses greater than those specified in Table 1810.8 in Sections 1811 and 1812 shall be permitted where supporting data justifying such higher stresses are filed and approved by the commissioner. Table 1810.8Allowable Axial Stresses for Materials Used in Deep Foundation Elements a Material Type and Condition Maximum Allowable Stress bMaterial Type and Condition Maximum Allowable Stress b1. Concrete or grout in compression c Cast-in-place with a permanent casing in accordance with Section 1812.5.20.4 f'c Cast-in-place in a pipe, tube, other permanent casing or rock0.33 f'c Cast-in-place without a permanent casing0.3 f'c Precast nonprestressed0.33 f'c Precast prestressed0.33 f'c - 0.27 fpc2. Nonprestressed reinforcement in compression0.4 fy ≤ 30,000 psi3. Structural steel in compression Cores within concrete-filled pipes or tubes0.5 Fy ≤ 32,000 psi Pipes, tubes or H-piles, where justified in accordance with Section 1810.4.1.5.10.5 Fy ≤ 32,000 psi Pipes or tubes for micropiles or caissons less than 14 inches in diameter0.4 Fy ≤ 32,000 psi Other pipes, tubes or H-piles0.35 Fy ≤ 16,000 psi Helical piles0.6Fy ≤ 0.5Fu4. Nonprestressed reinforcement in tension Within micropiles or caissons less than 14 inches in diameter0.6 fy Other conditions0.5 fy ≤ 24,000 psi5. Steel in tension Structural steel cores in caisson piles,0.5 Fy ≤ 32,000 psi Pipes, tubes or H-piles, where justified in accordance with Section 1810.4.1.5.10.5 Fy ≤ 32,000 psi Other pipes, tubes or H-piles0.35 Fy ≤ 16,000 psi Helical piles0.6 Fy ≤ 0.5 Fu6. TimberSee Section 1811.5.4 For SI: 1 pound per square inch = 6.895 kPa. a. For combined stresses, the structural capacity shall be computed in accordance with AISC 360 for steel piles and ACI 318 for concrete piles. b. f'c is the specified compressive strength of the concrete or grout; fpc is the compressive stress on the gross concrete section due to effective prestress forces only; fy is the specified yield strength of reinforcement; Fy is the specified minimum yield stress of steel; Fu is the specified minimum tensile stress of steel. c. The stresses specified apply to the gross cross-sectional area for precast concrete piles. The stresses specified shall apply to the concrete cross-sectional area for all other deep foundation elements. Where a temporary or permanent casing is used, the inside face of the casing shall be considered the concrete surface.
